Enabling marketing links that Stanford uses

Stanford uses the ABOUT, TOS, ROOT, and COURSES links, but none of
the others.

lms/envs/common.py

@@ -708,12 +708,12 @@ INSTALLED_APPS = (
 EDXMKTG_COOKIE_NAME = 'edxloggedin'
 MKTG_URLS = {}
 MKTG_URL_LINK_MAP = {
-    #'ABOUT': 'about_edx',
+    'ABOUT': 'about_edx',
     #'CONTACT': 'contact',
     #'FAQ': 'help_edx',
-    #'COURSES': 'courses',
-    #'ROOT': 'root',
-    #'TOS': 'tos',
+    'COURSES': 'courses',
+    'ROOT': 'root',
+    'TOS': 'tos',
     #'HONOR': 'honor',
     #'PRIVACY': 'privacy_edx',
 }